1. Field of the Invention
This invention provides an economical and convenient process for preparing 5-chloro- or 5-bromopyrimidine, by the high-temperature reaction of formamide with a 4-halo-5-hydroxy-2(5H)-furanone.
2. Prior Art
Pyrimidines have been studied by many organic chemists, and 5-halopyrimidines are frequently mentioned in the literature. For example, Kirby, U.S. Pat. No. 3,824,292, shows the preparation of 5-bromopyrimidine by the condensation of 2-bromo-3-methoxy-acrolein with formamide, citing Bredereck, Chem. Ber. 95, 803-09 (1962). The Bredereck article shows the preparation of 5-halopyrimidines by the reaction of formamide with 2-halotetraalkoxypropanes.
Another interesting preparation is shown by Budesinsky, Coll. Czech. Chem. Comm. 14, 223-35 (1949), C.A. 44, 1516e (1950), who prepared 4-carboxy-5-halo-2-substituted pyrimidines by the reaction of substituted amidines with 2,3-dihalo-3-carboxyacroleins.
A further item of interesting prior art is an article by Yanagita and Fukushima, J. Pharm. Soc. Japan 71, 39-40 (1951), who demonstrated the preparation of 5-chloro-2-aminopyrimidine by the reaction with guanidine of 2-chloro-3-hydroxyacrolein.
The invention described herein has a relationship to the processes of the prior art, but is clearly distinguished from the art by its ease and convenience, as well as by the obvious chemical distinctions.